I no longer trust descriptions
An insider could be trying to buy this cheap and as such included such a description, then they have a friend buy it for them.
The Storesman that deals with the stuff coming and going knows bugger-all, about machine tools. All he or she knows is what the user (wrong, or maliciously in error) tells him or her.
My buck would be on that someone who expected the lathe to 'just work', had no clues about the various gear trains that need be arranged, when switching from the various threading systems (module/DP, Metric/Inch, etc.) and like as not, IF the correct gears are there, they are improperly installed.
The only other mechanical failure that can throw off threading is if the shear pin on the lead screw is blown and only working by friction, occasionally slipping under load.
Even with a Quick Change Gear Box for thread cutting, it is standard to have a small selection of gears that need be changed, on these Colchesters. IIRC, there is a set of four or five gears that come as standard equipment, but I would have to check my manual for my Master 2500 to be positive. They are close enough in size, that switching them the wrong way around is pretty easy. Several of them are all within a tooth count of others.
Page 12 (page 10 of the scanned pages own page numbering) here
https://lathespares.com/pdf/colchester_master_2500.pdf shows the gears. Scanned page number 24 shows a pin PN 73607-0, that I believe is the shear pin for the lead screw (follow the LH bottom side of the page up, fifth item up, vertically on the page).
www.govdeals.com
